To install a curtain rod wall bracket, measure and mark the screw holes on the desired spots on the wall with a pencil. Use the length of the curtain rod as a guide when determining the best spots for brackets.
If the brackets fit snugly on the rod, it helps to attach the brackets to the rod and then have a one person hold the level against the top of the rod while the second person marks the holes. Set the rod and brackets aside. Drill holes at the marked spots with a small drill bit. Install anchors in the drilled holes, then put the bracket in position, and put the screws through the bracket holes and into the anchors. Repeat the bracket installation steps on the other side of the window frame.